This application is for the twelth Gordon Conference on Lysosomes, to be held June 23-29, 1986. It will be an interdisciplinary meeting, with speakers and participants drawn from the fields of cell biology, biochemistry, genetics, microbiology, physiology and pathology. Its focus will be on molecular approaches to lysosomes and related organelles. The field of "lysosomes" is now broadly perceived to include not only the classical degradative bodies, but also the organelles of endocytosis (coated pits and endosomes), of exocytosis (Golgi and secretory vesicles), and of biogenesis of lysosomes and their contents (endoplasmic reticulum and Golgi). The state of the art in the field includes the identification of specific molecules responsible for endocytosis, acidification, transport between organelles and degradative functions. Structural studies, as precise as current knowledge permits, will be presented for relevant proteins (e.g., enzymes and receptors) and whenever possible, for the nucleic acids in which they are encoded. Genetic studies permeate the program; nearly every session includes talks on the use of mutants and/or recombinant DNA technology. Thirty nine invited scientists, including speakers and chairpersons, are listed on the proposed program; they have been selected on the basis of major recent research contributions to the field. Ten additional speakers will be selected as important developments occur. We have tried as far as possible to invite younger investigators with new results. Other participants will be able to present their work in posters. The Conference is designed to facilitate communication and discussion between scientists in a fast-moving field that cuts across established disciplines of biomedical research.